This invention relates to tires and more particularly to an improved tread pattern for tires. It is well known in the tire industry that the choice of a particular tread design involves trade-off between specific tire performance characteristics. For example, a tread pattern which has good wet traction or snow traction is generally obtained at the expense of dry road traction, tread wear, rolling resistance, ride and noise level, and a tread pattern which has good tread wear and low rolling resistance is generally obtained at the expense of wet and snow traction. In the prior art when improved wet traction or improved hydroplaning performance was desired, the void volume in the tread area of the tire was simply increased by either enlarging the width of the grooves or by increasing the depth of the non-skid of the tread or by doing both. However, increasing the void volume in this manner generally results in a reduction in performance in dry traction, handling, tread wear and/or an increase in noise level.
Applicant has discovered a particular groove shape arrangement whereby acceptable levels of wet traction and hydroplaning characteristics of a tire are maintained while also maintaining or improving other performance characteristics such as rolling resistance, tread wear, noise levels, traction and handling.